UserImageLoader: Remove DCHECK requiring success of ReadFileToString().

chrome/browser/chromeos/login/user_image_loader.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_USER_IMAGE_LOADER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_USER_IMAGE_LOADER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 18 matching lines @@
                         public ImageDecoder::Delegate {
  public:
   // Callback used to return the result of an image load operation.
   typedef base::Callback<void(const UserImage& user_image)> LoadedCallback;
 
   // All file I/O, decoding and resizing are done via |background_task_runner|.
   UserImageLoader(
       ImageDecoder::ImageCodec image_codec,
       scoped_refptr<base::SequencedTaskRunner> background_task_runner);
 
-  // Load an image in the background and call |loaded_cb| with the result. If
-  // |size| is positive, the image is cropped to a square and shrunk so that it
-  // does not exceed |size|x|size|. The first variant of this method reads the
-  // image from |filepath| on disk, the second processes |data| read into memory
-  // already.
+  // Load an image in the background and call |loaded_cb| with the resulting
+  // UserImage (which may be empty in case of error). If |pixels_per_side| is
+  // positive, the image is cropped to a square and shrunk so that it does not
+  // exceed |pixels_per_side|x|pixels_per_side|. The first variant of this
+  // method reads the image from |filepath| on disk, the second processes |data|
+  // read into memory already.
   void Start(const std::string& filepath,
              int pixels_per_side,
              const LoadedCallback& loaded_cb);
   void Start(scoped_ptr<std::string> data,
              int pixels_per_side,
              const LoadedCallback& loaded_cb);
 
  private:
   friend class base::RefCountedThreadSafe<UserImageLoader>;
 
@@ skipping 42 matching lines @@
   // Holds information about the images currently being decoded. Accessed via
   // |background_task_runner_| only.
   ImageInfoMap image_info_map_;
 
   DISALLOW_COPY_AND_ASSIGN(UserImageLoader);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_USER_IMAGE_LOADER_H_